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Gabriel Gálik, Vladimír Kutiš, Jakub Jakubec, Juraj Paulech and Tibor Sedlár

Abstract

The article deals with modelling of coolant flow within the spent fuel storage pool of a VVER 440 reactor. The spent fuel storage pool is modelled in a state of standard reactor operation. The coolant heating from the remaining thermal power of stored spent fuel assemblies was also modelled.

Open access

Józef Rak

Abstract

The paper presents the full transient, two-dimensional finite volume method numerical calculations of the classical involute scroll compressor geometry. The purpose of the study was to develop and evaluate an adaptable implementation of numerical fluid mechanics and thermodynamics modeling procedure with a mesh deformation. The methodology consisting in the compression chamber geometry preparation, mesh generation and governing equations solving was described. The evaluation was carried by simulating an adiabatic compression process and the results were compared with the theoretical zero-dimensional model and the existing research concerning the scroll chamber computational fluid dynamics modeling. It has been shown that the proposed modeling routine results in good accuracy for the scroll compressors study applications.

Open access

Marek Jakubowski

Abstract

The whirlpool separator, used for hot trub separation, is prevalent in the brewing industry. It is a kind of a hydrocyclone inside of which a tea leaf effect occurs, which is sediment accumulation into a cone shape at the central part of the tank’s bottom. This manner of sediment accumulation is caused by the secondary flow occurring in the so-called Ekman boundary layer. This article is a summary of the research, which has been conducted for many years and involved observation, simulation and experimental research on the recognition and formation of the secondary flow accumulating the sediment cone. Secondary flows occurring in a whirlpool were identified through CFD simulation and PIV experiments, and are presented in this paper. Based on their location and direction, an attempt to determine their impact on the separation process taking place in the whirlpool has been made. The secondary flow identification methods proposed in this paper can be successfully applied in other solutions, e. g. structural ones, which involve rotational-flow-based separation.

Open access

M. Shabani and A. Mazahery

Computational Fluid Dynamics (CFD) Simulation of Liquid-Liquid Mixing in Mixer Settler

Mixer-settlers are widely used inmetallurgical, mineral and chemical process. One of the greatest challenges in the area of hydrometallurgy process simulation is agitation made by impeller inside mixer-settler which yet presents one of the most common operations. Computational fluid dynamics (CFD) model has been developed to predict the effect of different physical parameters including temperature and density on the mixing characteristics of the system. It is noted that non-isotropic nature of flow in a mixer-settler, the complex geometry of rotating impellers and the large disparity in geometric scales present are some of the factors which contribute to the simulation difficulty. The experimental data for different velocity outlet was also used in order to validate the model.

Open access

Vladimíra Michalcová, Sergej Kuznětsov and Stanislav Pospíšil

Abstracts

Article describes two different approaches of the solution of benchmark solution of bluff aerodynamic, which is the solution of wind pressures upon the cube exposed to the effects of air flow field. Physical modeling is carried out at the wind tunnel of the Institute of Theoretical and Applied Mechanics in Telč whereas numerical modeling is performed at the Faculty of Civil Engineering, VSB Technical University of Ostrava of software using Ansys Fluent.

Open access

Marek Mlkvik, Peter Hlbočan and Branislav Knížat

Abstract

The presented paper focuses on the CFD analysis of flows with a dominant tangential velocity component. A strong volumetric heat source is also present in the computational domain. This heat source represents the electric arc which heats the working medium and produces the plasma. The influence of the boundary conditions used herein on the presented flow is then discussed.

Open access

N. Kapilan, M. Manjunath Gowda and H. N. Manjunath

Abstract

The use of chlorofluorocarbon based refrigerants in the air-conditioning system increases the global warming and causes the climate change. The climate change is expected to present a number of challenges for the built environment and an evaporative cooling system is one of the simplest and environmentally friendly cooling system. The evaporative cooling system is most widely used in summer and in rural and urban areas of India for human comfort. In evaporative cooling system, the addition of water into air reduces the temperature of the air as the energy needed to evaporate the water is taken from the air. Computational fluid dynamics is a numerical analysis and was used to analyse the evaporative cooling system. The CFD results are matches with the experimental results.

Open access

P. Golewski and T. Sadowski

Abstract

The composites made of continuous fibers in the form of unidirectional and fabric prepregs are widely used in many fields of engineering for the production of lightweight and durable parts or whole structures. To achieve this, we not only need to possess knowledge of the composite mechanics, but also have to master the technology. In most cases, particularly for parts with advanced geometric shapes, autoclaving technique is used. The success of the carried out process occurs when the prepreg reaches the proper temperature throughout its volume in the specified time, where there are no overheated or unheated zones as well as when the prepreg is correctly pressed against the mold. In order to ensure adequate stiffness, the mold has much greater thickness than formed composite and the stiffening ribs. The result is that the time required for prepreg heating is greatly extended. To prevent this, the appropriate electric heaters embedded in the silicone grips are used.

The paper presents problems related to the mold structures and application of numerical methods aiming at early verification of the temperature and stress distribution. The coupled analysis of CFD (computational fluid dynamic) and heat transfer structural simulations were performed in Abaqus program. The studies were carried out for the airfoil fragment. A total of 12 simulations were conducted, 6 cases in which heat was supplied only from air flowing through the autoclave and 6 cases which included heaters inside the silicone grips. In the result the inhomogeneity of prepreg heating for each of the mold geometry was compared, and the average temperature was obtained after 60 seconds from the process initiation. Both the pressure inside the silicone grips (before inserting the mold into the autoclave) and the non-uniform temperature distribution result in the formation of stresses whose values were analyzed for molds made of aluminum. For this purpose the temperature dependent elastic – plastic material model was used for aluminum molds.

Open access

Waldemar Kołodziejczyk

Abstract

The objective of this paper is to discuss some of the issues associated with environmental load on the three-link serial manipulator caused by underwater current. We have conducted CFD simulations to investigate hydrodynamic effects induced by changing current direction and changing with time current speed in order to better understand the physics of the problem. The results are presented in terms of moments of hydrodynamic forces plotted against relative position of the current and the robotic arm. Time history of hydrodynamic loads according to periodically changing current speed is presented and discussed.

Open access

Leszek Remiorz, Sebastian Rulik and Sławomir Dykas

Abstract

Paper presents the results of numerical modelling of a rectangular tube filled with a mixture of air and CO2 by means of the induced standing wave. Assumed frequency inducing the acoustic waves corresponds to the frequency of the thermoacoustic engine. In order to reduce the computational time the engine has been replaced by the mechanical system consisting of a piston. This paper includes the results of model studies of an acoustic tube filled with a mixture of air and CO2 in which a standing wave was induced.